PLANET EARTH: Seasonal Forests

Transcription

1 PLANET EARTH: Seasonal Forests Teacher s Guide Grade Level: 6-8 Running Time: 42 minutes Program Description Investigate temperate forests and find some of the most elusive creatures and welladapted plant life on Earth. The program accentuates the distinctive characteristics of coniferous and deciduous trees, including leaf types and reproduction, during each of the four seasons as well as how insects and animals rely on a variety of trees for food, shelter, and clean air. Each highlighted animal exhibits unique adaptations like the moose s ability to eat conifer needles and the miniature stature of the species living in Chile s Valdivian forests where food is scarce to survive the harsh seasonal changes of the forests. Home to such endangered animals as the Amur leopard and Eurasian black vulture, the forest habitat plays an important role in Earth s ecosystem. Learning Objectives After viewing the program and participating in discussion, students will be able to: Describe the characteristics of a seasonal forest; Explain the relationship between resources and population size in an ecosystem; Communicate how energy is transferred in a food web and define the terms producer and consumer; Relate an organism s adaptations to its surrounding habitat; Recognize the importance of Earth s natural resources and the impact humans have on forest habitats. Classroom Connections Why is it important to maintain the health of the world s forests? Where do the world s oldest trees live? Locate the taiga on a map and describe its characteristics. Describe the conditions of living in the taiga. What types of plants and animals can survive there? How have such animals as the moose and capercaillie adapted to the lack of food in the taiga? How do animals living in forests depend on each other for survival? What is unique about the animals living in South America s Valdivian forests? What might be one reason for the adaptation? How have the animals adaptations allowed them to survive? 1

2 Draw the life cycle of the periodical cicada and label each key step. Use your drawing to describe the process to a partner. Create a Venn diagram to compare and contrast the characteristics of deciduous and conifer trees. Why do deciduous trees lose their leaves? Describe the annual seasonal changes that take place in the temperate forests of North America. How do conifer trees reproduce? What role do animals play in their reproductive efforts? Classroom Activities Develop an understanding that most of our oxygen comes from trees through the process of photosynthesis. To begin the activity, gather clear eight-ounce plastic cups, boiled and cooled water (to deplete chlorine) with a little baking soda added to provide carbon dioxide, and small aquarium plants. Divide the students into small groups. Provide two cups and two plant sprigs to each group. Instruct students to place a plant sprig in each cup and fill it with the chlorine-free water. Each group should place one cup on a window sill or under another direct light source. The second cup should be placed in a dark place, like a cupboard. Observe each plant at five-minute intervals up to fifteen minutes. Students should use drawings to record all observations in a science notebook. Have students make a hypothesis about what is taking place in the cups. They should include information about what the bubbles are and give a reason for why the cup in the cupboard has little or no bubbles. Explain the process of photosynthesis as the chemical process plants use to change chemicals and nutrients into food. For photosynthesis to take place, sunlight and carbon dioxide must be available. Oxygen is a byproduct of the chemical process and is released into the air through openings in the leaves called stomata. With this new understanding of photosynthesis, ask students to evaluate their previous hypotheses. What are the bubbles? Why are the bubbles only present in the cup on the windowsill? Why did the cup in the cupboard not produce any bubbles? Why are plants and trees important to animals and humans? What do they provide for us? What do we give to them? What would happen if we lost a large portion of the Earth s forests? Study plants and animals living in a temperate forest and create a food web. Have students create a list of plants and animals that live in the temperate deciduous forest or a forest that has four distinct seasons. Include plants and animals shown in the program as well as the inhabitants students are aware of from personal experience. Define the three major types of organisms in the food chain producers, consumers, and decomposers. Have students label each animal on the list as a producer, consumer, or decomposer. Break down the consumers into three types herbivores, carnivores, and omnivores and label each. Define a food web as a visual representation of how plants and animals rely on each other for food and energy. 2

3 Divide students into groups of two and assign one animal from the brainstormed list to each group to research. Students should work together to answer the following questions: What does the organism look like? What does the organism eat? What predators eat this organism? Does this organism s food source change along with the seasons? How does the organism adapt to the forest s seasonal changes? Is the organism a producer or consumer? Once the research is complete, have students make a food web for their organism during two seasons of the year. Each web should include at least five other organisms. Students should label the web as relevant during spring, summer, winter, or fall. Have students share their webs with another group and explain how each organism relies on the seasons. Ask students to identify the Earth s natural resources. How many of these resources come from or rely on forests? How do we rely on these resources to survive? What would happen if they disappeared? In small groups, ask students to make a list of what people in their communities are doing to protect such natural resources as trees and water. Ask students to make a list of what they, along with their families, are doing to help conserve resources. Ask students to look at their lists and evaluate if more could be done to help protect the environment. Over the next day or so, have students survey their actions and the actions of others at home and school to come up with additional ways to conserve resources. In the next class period, have students discuss what they learned with their group members and decide on an area of conservation they d like to improve. Have each group devise an action plan to protect natural resources within the school or community. Each group member should produce two paragraphs defining the problem as well as persuading readers to take a specific action to conserve natural resources. Create a class newsletter to raise awareness of environmental problems and offer ways to take responsibility for the health of the Earth. Target Vocabulary* adaptation - modification of an organism or its parts that makes it more fit for existence under the conditions of its environment behavior - a: anything that an organism does involving action and response to stimulation; b: the response of an individual, group, or species to its environment biome - a major ecological community type (as tropical rain forest, grassland, or desert) conifer - any of an order (Coniferales) of mostly evergreen trees and shrubs having usually needle-shaped or scalelike leaves and including forms (as pines) with true cones and others (as yews) with an arillate fruit deciduous - falling off or shed seasonally or at a certain stage of development in the life cycle 3

4 ecosystem - the complex of a community of organisms and its environment functioning as an ecological unit erode - to wear away by the action of water, wind, or glacial ice (flooding eroded the hillside) food chain - an arrangement of the organisms of an ecological community according to the order of predation in which each uses the next usually lower member as a food source food web - the totality of interacting food chains in an ecological community habitat - the place or environment where a plant or animal naturally or normally lives and grows predator - an animal that lives by predation (a mode of life in which food is primarily obtained by the killing and consuming of animals) prey - an animal taken by a predator as food taiga- a moist subarctic forest dominated by conifers (as spruce and fir) that begins where the tundra ends temperate - having a moderate climate which especially lacks extremes in temperature tropics - either of the two parallels of terrestrial latitude at a distance of about twentythree degrees north or south of the equator where the sun is directly overhead when it reaches its most northerly or southerly point in the sky *By permission. From the Merriam-Webster Online Dictionary 2007 by Merriam-Webster, Incorporated ( Academic Standards National Science Education Standards (National Research Council, NAS, 1996) The National Academy of Sciences provides guidelines for teaching science in grades K 12 to promote scientific literacy. Standards specific to this PLANET EARTH program: Grades 5 8: Regulation and Behavior (p. 157) Populations and Ecosystems (pp ); Diversity and Adaptations of Organisms (p. 158); Populations, Resources, and Environments (p. 168) To view the standards, visit the NSES Web site: 4

5 AAAS Benchmarks for Science Literacy Developed by the American Association for the Advancement of Science (AAAS), Benchmarks for Science Literacy states what all students should know and be able to do in science, mathematics, and technology by the end of grades 2, 5, 8, and 12. Benchmarks addressed in this PLANET EARTH program: Chapter 5: Diversity of Life (pp ); Interdependence of Life (p. 117); Flow of Matter and Energy (pp ); Evolution of Life (pp ) Chapter 4: The Earth (pp ) AAAS Benchmarks for Science Literacy is available on the Web at: Published by Discovery Education, Inc., a division of Discovery Communications, LLC All rights reserved. Based on PLANET EARTH BBC. Distributed under exclusive license from Educational Publishers LLP. 5